accessibilityrenderobject.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
* Copyright (C) 2008 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1.  Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
* 2.  Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in the
*     documentation and/or other materials provided with the distribution.
* 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
*     its contributors may be used to endorse or promote products derived
*     from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include "config.h"
#include "AccessibilityRenderObject.h"

#include "AXObjectCache.h"
#include "AccessibilityListBox.h"
#include "AccessibilityImageMapLink.h"
#include "CharacterNames.h"
#include "EventNames.h"
#include "FloatRect.h"
#include "FocusController.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "HTMLAreaElement.h"
#include "HTMLFrameElementBase.h"
#include "HTMLImageElement.h"
#include "HTMLInputElement.h"
#include "HTMLLabelElement.h"
#include "HTMLMapElement.h"
#include "HTMLOptGroupElement.h"
#include "HTMLOptionElement.h"
#include "HTMLOptionsCollection.h"
#include "HTMLSelectElement.h"
#include "HTMLTextAreaElement.h"
#include "HitTestRequest.h"
#include "HitTestResult.h"
#include "LocalizedStrings.h"
#include "NodeList.h"
#include "NotImplemented.h"
#include "Page.h"
#include "RenderFieldset.h"
#include "RenderFileUploadControl.h"
#include "RenderImage.h"
#include "RenderInline.h"
#include "RenderListBox.h"
#include "RenderListMarker.h"
#include "RenderMenuList.h"
#include "RenderText.h"
#include "RenderTextControl.h"
#include "RenderTheme.h"
#include "RenderView.h"
#include "RenderWidget.h"
#include "SelectionController.h"
#include "Text.h"
#include "TextIterator.h"
#include "htmlediting.h"
#include "visible_units.h"
#include <wtf/StdLibExtras.h>

using namespace std;

namespace WebCore {

using namespace HTMLNames;

AccessibilityRenderObject::AccessibilityRenderObject(RenderObject* renderer)
    : m_renderer(renderer)
    , m_ariaRole(UnknownRole)
{
    setAriaRole();
#ifndef NDEBUG
    m_renderer->setHasAXObject(true);
#endif
}

AccessibilityRenderObject::~AccessibilityRenderObject()
{
    ASSERT(isDetached());
}

PassRefPtr<AccessibilityRenderObject> AccessibilityRenderObject::create(RenderObject* renderer)
{
    return adoptRef(new AccessibilityRenderObject(renderer));
}

void AccessibilityRenderObject::detach()
{
    clearChildren();
    AccessibilityObject::detach();
    
#ifndef NDEBUG
    if (m_renderer)
        m_renderer->setHasAXObject(false);
#endif
    m_renderer = 0;    
}

AccessibilityObject* AccessibilityRenderObject::firstChild() const
{
    if (!m_renderer)
        return 0;
    
    RenderObject* firstChild = m_renderer->firstChild();
    if (!firstChild)
        return 0;
    
    return m_renderer->document()->axObjectCache()->getOrCreate(firstChild);
}

AccessibilityObject* AccessibilityRenderObject::lastChild() const
{
    if (!m_renderer)
        return 0;
    
    RenderObject* lastChild = m_renderer->lastChild();
    if (!lastChild)
        return 0;
    
    return m_renderer->document()->axObjectCache()->getOrCreate(lastChild);
}

AccessibilityObject* AccessibilityRenderObject::previousSibling() const
{
    if (!m_renderer)
        return 0;
    
    RenderObject* previousSibling = m_renderer->previousSibling();
    if (!previousSibling)
        return 0;
    
    return m_renderer->document()->axObjectCache()->getOrCreate(previousSibling);
}

AccessibilityObject* AccessibilityRenderObject::nextSibling() const
{
    if (!m_renderer)
        return 0;
    
    RenderObject* nextSibling = m_renderer->nextSibling();
    if (!nextSibling)
        return 0;
    
    return m_renderer->document()->axObjectCache()->getOrCreate(nextSibling);
}

AccessibilityObject* AccessibilityRenderObject::parentObjectIfExists() const
{
    if (!m_renderer)
        return 0;
    
    RenderObject *parent = m_renderer->parent();
    if (!parent)
        return 0;

    return m_renderer->document()->axObjectCache()->get(parent);
}
    
AccessibilityObject* AccessibilityRenderObject::parentObject() const
{
    if (!m_renderer)
        return 0;
    
    RenderObject *parent = m_renderer->parent();
    if (!parent)
        return 0;
    
    if (ariaRoleAttribute() == MenuBarRole)
        return m_renderer->document()->axObjectCache()->getOrCreate(parent);

    // menuButton and its corresponding menu are DOM siblings, but Accessibility needs them to be parent/child
    if (ariaRoleAttribute() == MenuRole) {
        AccessibilityObject* parent = menuButtonForMenu();
        if (parent)
            return parent;
    }
    
    return m_renderer->document()->axObjectCache()->getOrCreate(parent);
}

bool AccessibilityRenderObject::isWebArea() const
{
    return roleValue() == WebAreaRole;
}

bool AccessibilityRenderObject::isImageButton() const
{
    return isNativeImage() && roleValue() == ButtonRole;
}

bool AccessibilityRenderObject::isAnchor() const
{
    return !isNativeImage() && isLink();
}

bool AccessibilityRenderObject::isNativeTextControl() const
{
    return m_renderer->isTextControl();
}
    
bool AccessibilityRenderObject::isTextControl() const
{
    AccessibilityRole role = roleValue();
    return role == TextAreaRole || role == TextFieldRole;
}

bool AccessibilityRenderObject::isNativeImage() const
{
    return m_renderer->isImage();
}    
    
bool AccessibilityRenderObject::isImage() const
{
    return roleValue() == ImageRole;
}

bool AccessibilityRenderObject::isAttachment() const
{
    if (!m_renderer)
        return false;
    
    // Widgets are the replaced elements that we represent to AX as attachments
    bool isWidget = m_renderer && m_renderer->isWidget();
    ASSERT(!isWidget || (m_renderer->isReplaced() && !isImage()));
    return isWidget && ariaRoleAttribute() == UnknownRole;
}

bool AccessibilityRenderObject::isPasswordField() const
{
    ASSERT(m_renderer);
    if (!m_renderer->node() || !m_renderer->node()->isHTMLElement())
        return false;
    if (ariaRoleAttribute() != UnknownRole)
        return false;

    InputElement* inputElement = toInputElement(static_cast<Element*>(m_renderer->node()));
    if (!inputElement)
        return false;

    return inputElement->isPasswordField();
}

bool AccessibilityRenderObject::isCheckboxOrRadio() const
{
    AccessibilityRole role = roleValue();
    return role == RadioButtonRole || role == CheckBoxRole;
}    
    
bool AccessibilityRenderObject::isFileUploadButton() const
{
    if (m_renderer && m_renderer->node() && m_renderer->node()->hasTagName(inputTag)) {
        HTMLInputElement* input = static_cast<HTMLInputElement*>(m_renderer->node());
        return input->inputType() == HTMLInputElement::FILE;
    }
    
    return false;
}
    
bool AccessibilityRenderObject::isInputImage() const
{
    if (m_renderer && m_renderer->node() && m_renderer->node()->hasTagName(inputTag)) {
        HTMLInputElement* input = static_cast<HTMLInputElement*>(m_renderer->node());
        return input->inputType() == HTMLInputElement::IMAGE;
    }
    
    return false;
}

bool AccessibilityRenderObject::isProgressIndicator() const
{
    return roleValue() == ProgressIndicatorRole;
}

bool AccessibilityRenderObject::isSlider() const
{
    return roleValue() == SliderRole;
}
    
bool AccessibilityRenderObject::isMenuRelated() const
{
    AccessibilityRole role = roleValue();
    return  role == MenuRole ||
            role == MenuBarRole ||
            role == MenuButtonRole ||
            role == MenuItemRole;
}    

bool AccessibilityRenderObject::isMenu() const
{
    return roleValue() == MenuRole;
}

bool AccessibilityRenderObject::isMenuBar() const
{
    return roleValue() == MenuBarRole;
}

bool AccessibilityRenderObject::isMenuButton() const
{
    return roleValue() == MenuButtonRole;
}

bool AccessibilityRenderObject::isMenuItem() const
{
    return roleValue() == MenuItemRole;
}
     
bool AccessibilityRenderObject::isPressed() const
{
    ASSERT(m_renderer);
    if (roleValue() != ButtonRole)
        return false;

    Node* node = m_renderer->node();
    if (!node)
        return false;

    // If this is an ARIA button, check the aria-pressed attribute rather than node()->active()
    if (ariaRoleAttribute() == ButtonRole) {
        if (equalIgnoringCase(getAttribute(aria_pressedAttr).string(), "true"))
            return true;
        return false;
    }

    return node->active();
}

bool AccessibilityRenderObject::isIndeterminate() const
{
    ASSERT(m_renderer);
    if (!m_renderer->node() || !m_renderer->node()->isElementNode())
        return false;

    InputElement* inputElement = toInputElement(static_cast<Element*>(m_renderer->node()));
    if (!inputElement)
        return false;

    return inputElement->isIndeterminate();
}

bool AccessibilityRenderObject::isChecked() const
{
    ASSERT(m_renderer);
    if (!m_renderer->node() || !m_renderer->node()->isElementNode())
        return false;

    InputElement* inputElement = toInputElement(static_cast<Element*>(m_renderer->node()));
    if (!inputElement)
        return false;

    return inputElement->isChecked();
}

bool AccessibilityRenderObject::isHovered() const
{
    ASSERT(m_renderer);
    return m_renderer->node() && m_renderer->node()->hovered();
}

bool AccessibilityRenderObject::isMultiSelect() const
{
    ASSERT(m_renderer);
    if (!m_renderer->isListBox())
        return false;
    return m_renderer->node() && static_cast<HTMLSelectElement*>(m_renderer->node())->multiple();
}
    
bool AccessibilityRenderObject::isReadOnly() const
{
    ASSERT(m_renderer);
    
    if (isWebArea()) {
        Document* document = m_renderer->document();
        if (!document)
            return true;
        
        HTMLElement* body = document->body();
        if (body && body->isContentEditable())
            return false;
        
        Frame* frame = document->frame();
        if (!frame)
            return true;
        
        return !frame->isContentEditable();
    }

    return !m_renderer->node() || !m_renderer->node()->isContentEditable();
}

bool AccessibilityRenderObject::isOffScreen() const
{
    ASSERT(m_renderer);
    IntRect contentRect = m_renderer->absoluteClippedOverflowRect();
    FrameView* view = m_renderer->document()->frame()->view();
    FloatRect viewRect = view->visibleContentRect();